1. Field of the Disclosure
The present disclosure generally relates to improvements to a power distribution system and method, and more particularly to advanced power calculations and user interfaces to improve reliability and energy efficiency of a power distribution system, such as an intelligent power strip, and user or operator interaction with such a system.
2. Discussion of Related Art
Intelligent rack-mounted power distribution units, sometimes referred to as “rack PDUs,” may include at least one branch input power feed, single or three phase, with multiple receptacles to power attached equipment. Rack PDUs often include metering functions to measure and calculate voltage, current, power, and environmental data as well as a processor, memory and network management device for remote communication and management. Historically, rack PDUs measure aggregate load data based on phases and/or breaker banks, most often feeding multiple receptacle outputs. New generations of rack PDUs may now include metering loads at each individual receptacle output. An exemplary rack PDU is disclosed in U.S. Pat. No. 6,741,442, which is assigned to American Power Conversion Corporation of West Kingston, R.I., the assignee of the present disclosure, which is incorporated herein by reference in its entirety for all purposes.
For example, FIG. 1 illustrates a known power distribution unit, generally indicated at 10, having a vertical mount form factor suitable for mounting within a typical equipment rack (not shown). As shown, the power distribution unit 10 is connected to a 3-pole branch circuit breaker 12 having three phases L1, L2, L3. In other embodiments, the power distribution unit 10 may have a single phase L1. The branch circuit breaker 12 feeds power to the power distribution unit 10, which may be configured to have several sub-branch breakers, which are identified as B1, B2, B3, B4, B5, B6. In the shown example, an input branch circuit feed 14 is 3-phase. In a 208 Volt example, the input branch circuit feed 14 is broken down into six breaker banks having outlet receptacles, identified by reference number 16, with an outlet number identifier associated with the reference number. The arrangement is such that each 2-pole branch circuit breaker (B1, B2, B3, B4, B5, B6) of the power distribution unit 10 is fed by two of the incoming phases and feeds one or more outlet receptacles 16 at 208 Volts. In the shown example, the power distribution unit 10 includes six branch circuit breakers, each having two outlet receptacles. Thus, the power distribution unit 10 includes twelve outlet receptacles 16, which may be connected to IT loads, such as servers. Current is measured by a sensor associated with the branch circuit breaker 12 for each incoming branch circuit breaker phase (L1, L2, L3) and a sensor associated with each circuit breaker (B1, B2, B3, B4, B5, B6) on the rack power distribution unit.
Real-time measurements may be displayed locally by a local user display 18, which is illustrated separately from the power distribution unit 10 in FIG. 1. Presently available rack power distribution units provide the raw metered data, which may be fed to external data logs or software programs to help users calculate the information necessary to make upgrade, planning, worst case, or reliability calculations. However, none of these rack power distribution units provide feedback to the operator incorporating the historical current measurements of the single or three phase input and the circuit breakers to improve the management and efficiency of the rack power distribution units in applying new loads to the power distribution unit.